Seepage and percolation losses in irrigating paddy on the river terraces of Nepal | |
| Author | Adhikary, Yuva Raj |
| Call Number | AIT Thesis no.WA-87-3 |
| Subject(s) | Soil percolation Seepage |
| Note | A thesis study submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Abstract | Of the various loss components of irrigation water, seepage and percolation is observed to be the highest in the river terrace soils in the hills of Nepal due to their complex geological formations and poor management practices. These losses have been assumed to be the main causes of high water requirement of crop resulting into the limited achievement of irrigation No systematic measurements of such losses have been reported so far . Although studies have been reported in the past for the lowland paddy soils, the knowledge of seepage and percolation losses on the river terraces in the hills is limited because of the complexity of phenomenon and the incomplete studies made so far. This study is concerned with the seepage and percolation losses in a typic al river terrace of Nepal. The research area was selected in central Nepal on the Trishuli river terrace which is a representative area for most of the river terraces in the hills of Nepal. Various sites were selected and controlled field measurements were carried out throughout the growing season of paddy. Experiments were conducted in the fields with and without paddy to study the effect of root development with the growth of paddy. Also continuous and rotational irrigation practices were employed and the effect of the drainage was studied . In general, high and varying rates of seepage and percolation losses were observed. The observations and the analyses s how that there exists a great variability in seepage and percolation rates from the fields , and in a single field, these rates fluctuate day to day. Some fields within a little area of less than one hundred hectares indicate a steep increase of seepage and percolation with the growth of the paddy, some show a mild rise while there are cases showing the decrease of these values, mainly due to the varied soil and water management practices, effect of previous crops and inhomogeneity of the soils . |
| Year | 1987 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Water Resources Research Engineering (WA) |
| Chairperson(s) | Paudyal, Guna N. |
| Examination Committee(s) | Mizutani, Masakazu ;Loof, Rainer ;Nielsen, Jens Moller |
| Scholarship Donor(s) | The Government of Japan |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1987 |